.App {
  width           : 100vw;
  height          : 100vh;
  text-align      : center;
  background-color: black;
  display         : flex;
  justify-content : center;
}

.cover-icon {
  background-image: url('../../resource/cover.png');
  background-size : 50vw 50vw;
  width           : 50vw;
  height          : 50vw;
  margin-top      : 20vh;
}

.start-button {
  color            : white;
  font-style       : italic;
  margin-top       : 30vh;
  animation        : highlight 3s infinite;
  -webkit-animation: highlight 3s infinite;
}

@keyframes highlight {
  0% {
    opacity: 0;
  }

  5% {
    opacity: 0.125;
  }

  10% {
    opacity: 0.25;
  }

  15% {
    opacity: 0.375;
  }


  20% {
    opacity: 0.5;
  }

  25% {
    opacity: 0.625;
  }


  30% {
    opacity: 0.75;
  }

  35% {
    opacity: 0.875;
  }


  40% {
    opacity: 1;
  }

  60% {
    opacity: 1;
  }

  65% {
    opacity: 0.875;
  }


  70% {
    opacity: 0.75;
  }

  75% {
    opacity: 0.625;
  }


  80% {
    opacity: 0.5;
  }

  85% {
    opacity: 0.375;
  }


  90% {
    opacity: 0.25;
  }

  95% {
    opacity: 0.125;
  }

  100% {
    opacity: 0;
  }
}

@-webkit-keyframes highlight {
  0% {
    opacity: 0;
  }

  5% {
    opacity: 0.125;
  }

  10% {
    opacity: 0.25;
  }

  15% {
    opacity: 0.375;
  }


  20% {
    opacity: 0.5;
  }

  25% {
    opacity: 0.625;
  }


  30% {
    opacity: 0.75;
  }

  35% {
    opacity: 0.875;
  }


  40% {
    opacity: 1;
  }

  60% {
    opacity: 1;
  }

  65% {
    opacity: 0.875;
  }


  70% {
    opacity: 0.75;
  }

  75% {
    opacity: 0.625;
  }


  80% {
    opacity: 0.5;
  }

  85% {
    opacity: 0.375;
  }


  90% {
    opacity: 0.25;
  }

  95% {
    opacity: 0.125;
  }

  100% {
    opacity: 0;
  }
}